Lyons started quickly, scoring five points in the opening 41/2 minutes.
"Mark is filled with confidence and, when he gets his confidence going, it's contagious on our entire team," said coach Sean Miller.
According to Miller, this is fourth time a team with Lyons as a member has reached the Sweet 16.
As a partial-qualifier, he didn't play in his first season at Xavier, but he practiced every day and the Musketeers advanced.
Once he got on the court, Lyons helped two more Xavier teams to the Sweet 16 before transferring to Arizona for his last year of eligibility.
"I think it's remarkable," Miller said. "Really, it shows you the [big] games really brings out the best in him."
The tooth hurts
Harvard freshman point guard Siyani Chambers was hit in the mouth 57 seconds into the second half and lost a tooth.
While officials reviewed the play, Arizona's Kevin Parrom had his right elbow treated by team trainers in front of the Wildcat bench.
No foul was called on the play and, after leaving the game briefly, Chambers returned. He finished with a team-high 10 points.
"I don't know," Chambers said. "I got a rebound, kicked it out and was going up the court for a fast break. I saw Christian [Webster] on the wing and tried to throw it to him. I went up in the air, came down and before I knew it my tooth was out."